Tri-axis force sensor

ABSTRACT

An input device includes a movable input surface protruding from an electronic device. The input device enables force inputs along three axes relative to the electronic device: first lateral movements, second lateral movements, and axial movements. The input device includes force or displacement sensors which can detect a direction and magnitude of input forces.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a nonprovisional patent application of and claimsthe benefit of U.S. Provisional Patent Application No. 62/533,994, filedJul. 18, 2017 and titled “Tri-Axis Force Sensor,” the disclosure ofwhich is hereby incorporated by reference herein in its entirety.

FIELD

The described embodiments relate generally to input devices. Moreparticularly, the present embodiments relate to multi-axial pressureinput devices, such as a watch crown, coupled to electronic devices.

BACKGROUND

Many devices, such as wearable electronic devices, use various inputmechanisms to receive user input. In particular, small form factordevices, such as watches, smart watches, wearable devices, and so on,may have a limited number of input mechanisms.

For example, many watches include a crown or similar input mechanism.Some crowns can be rotated to wind the watch. Other crowns may betranslated into a time-changing position whereupon they may be rotatedto change the time of the watch.

SUMMARY

The present disclosure relates to an input mechanism, such as a watchcrown, that detects applied force along multiple axes. The inputmechanism may be included in an electronic device. A user may provideinput to the electronic device by applying force axially (e.g., along anaxis of rotation of the input mechanism), laterally (e.g., perpendicularto the axis of rotation), or rotationally (e.g., rotating about the axisof rotation). The input mechanism may include two or more force sensorsthat may be used to determine a magnitude and direction of a forceapplied to the watch crown. The electronic device may be used to receivea variety of different inputs based on various directions and magnitudesof force applied to the watch crown.

A watch may include a housing, a display at least partially within thehousing, a crown, and a processor. The crown includes a stud coupled to,and protruding from, the housing of the watch. A compliant materialsurrounds at least a portion of the stud, and a crown cap at leastpartially surrounds the compliant material. A force sensor is positionedwithin the compliant material, and the processor is coupled to the forcesensor. The stud also defines an opening which facilitates an electricalconnection between the processor and the force sensor.

In some examples, the force sensor includes a first electrode, a secondelectrode, and an insulating substrate between the first electrode andthe second electrode. The force sensor is configured to detect amovement of the crown cap based on a change in distance between thefirst electrode and the second electrode.

An input device may include a stud configured to couple to, and protrudefrom, an electronic device, a compliant material surrounding at least aportion of the stud, and a crown cap at least partially surrounding thecompliant material. The crown cap is configured to move relative to thestud. A first sensor is configured to transmit a first signal inresponse to the movement of the cap relative to the stud, and a secondsensor is configured to transmit a second signal in response to themovement of the cap relative to the stud. A processor is coupled to thefirst sensor and the second sensor, and the processor is configured tocorrelate the first signal and the second signal to an input.

A method of detecting a force applied to a crown of a watch includes theoperation of detecting a movement of the crown relative to the watch inresponse to application of the force using a first force sensor and asecond force sensor. A first force value is determined which correlatesto the first force sensor, and a second force value is determined whichcorrelates to the second force sensor. The first force value and thesecond force value are compared to a stored input profile to determine adirection of an input to the crown.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like elements.

FIG. 1 depicts an electronic device in the form of an electronic watch,incorporating an example watch crown according to the presentdisclosure.

FIG. 2 depicts a cross-section of an example embodiment of a watch crowncoupled to the housing of the electronic device of FIG. 1, taken alongline A-A of FIG. 1.

FIG. 3 depicts a sample cross-section of a watch crown, illustrating astud and a force sensor.

FIG. 4A depicts a sample cross-section of the watch crown at a firstposition, in which no force is applied to the crown cap.

FIG. 4B depicts the watch crown in a second position, in response to auser's application of an axial force to the crown cap.

FIG. 4C depicts the watch crown in a third position, in response to auser's application of a lateral force to the crown cap.

FIG. 4D depicts the watch crown in a fourth position, in response to auser's application of an oblique force to the crown cap.

FIG. 4E depicts the watch crown in a fifth position, in response to arotation of the crown cap.

FIG. 5A depicts a sample cross-section of the watch crown, with certainelements removed to better illustrate a force sensor.

FIG. 5B depicts a sample cross-section of the watch crown, with certainelements removed to better illustrate a second example of a forcesensor.

FIG. 5C depicts a sample cross-section of the watch crown, with certainelements removed to better illustrate a third example of a force sensor.

FIG. 6 depicts a cross-section of another example embodiment of a watchcrown coupled to the housing of the electronic device of FIG. 1, takenalong line A-A of FIG. 1.

FIG. 7 depicts a cross-section of another example embodiment of a watchcrown coupled to the housing of the electronic device of FIG. 1, takenalong line A-A of FIG. 1.

FIG. 8 depicts a cross-section of another example embodiment of a watchcrown coupled to the housing of the electronic device of FIG. 1, takenalong line A-A of FIG. 1.

FIG. 9A depicts an example electronic device having a watch crown and adisplay depicting example graphics.

FIG. 9B depicts the electronic device of FIG. 9A, illustrating how thegraphics shown on the display change as the watch crown rotates.

FIG. 10A depicts an example electronic device with a display depictinganother example of a graphic.

FIG. 10B depicts the electronic device of FIG. 10A, illustrating anexample zoom operation in response to application of force to the crown.

FIG. 11A depicts an example electronic device with a display depictinganother example of a graphic.

FIG. 11B depicts the electronic device of FIG. 11A, illustrating usingthe watch crown to change an operational state of the electronic deviceor otherwise toggle between inputs.

FIG. 12 depicts a schematic representation of example components of anelectronic device.

The use of cross-hatching or shading in the accompanying figures isgenerally provided to clarify the boundaries between adjacent elementsand also to facilitate legibility of the figures. Accordingly, neitherthe presence nor the absence of cross-hatching or shading conveys orindicates any preference or requirement for particular materials,material properties, element proportions, element dimensions,commonalities of similarly illustrated elements, or any othercharacteristic, attribute, or property for any element illustrated inthe accompanying figures.

Additionally, it should be understood that the proportions anddimensions (either relative or absolute) of the various features andelements (and collections and groupings thereof) and the boundaries,separations, and positional relationships presented therebetween, areprovided in the accompanying figures merely to facilitate anunderstanding of the various embodiments described herein and,accordingly, may not necessarily be presented or illustrated to scale,and are not intended to indicate any preference or requirement for anillustrated embodiment to the exclusion of embodiments described withreference thereto.

DETAILED DESCRIPTION

Reference will now be made in detail to representative embodimentsillustrated in the accompanying drawings. It should be understood thatthe following descriptions are not intended to limit the embodiments toone preferred implementation. To the contrary, the described embodimentsare intended to cover alternatives, modifications, and equivalents ascan be included within the spirit and scope of the disclosure and asdefined by the appended claims.

An electronic device is disclosed herein, which may facilitateinteraction with a user. The electronic device may be a wearable device,such as a watch, and may include a touch screen operative to receiveinputs from a user. The watch may include a crown as an additional inputmechanism capable of receiving multi-directional input from the user.Generally, the crown is coupled to a housing of the watch at a locationsimilar to a traditional mechanical watch.

The crown may receive force or displacement input from a user alongthree axes relative to its attachment point on a side of the watchhousing when the device is in use: x (e.g., in a first lateraldirection, relative to the housing), y (e.g., in a second lateraldirection, relative to the housing), and z (e.g., into or out of thehousing) (see, e.g., FIG. 2). The crown may receive rotational force ordisplacement input as well (e.g., rotating about the z axis shown inFIG. 2). Force or displacement sensors may be included within the crownand/or watch housing to detect force inputs. Generally, force inputs tothe crown may cause a displacement of the crown (or a portion of thecrown), and may accordingly be detected by force or displacementsensors. One or more sensors may enable the watch to distinguish adegree and/or direction of an input to the crown. These or additionalsensors may further detect rotational input to the crown.

A traditional watch crown may detect only rotation of the crown as aninput. The tri-axial crown of the present disclosure enables additionalinput to the crown, such as pressing the crown as a button, moving thecrown up and down to scroll through options, moving the crown back andforth to adjust a volume or brightness level of the watch, or otherwisechanging an indicium (or indicia) on a display of the electronic device.As used herein, an “indicium” is any text, graphic, icon, symbol, or thelike, Sample indicia include application icons, volume indicators,brightness indicators, data shown in a list, power indicators, words,numbers, and so on. “Indicia” is the plural of “indicium.”

In some embodiments, these additional inputs may further enableintelligent processing of detected forces applied to the crown. Forexample, a motion of a wearer's wrist may be falsely detected as adeliberate crown input (e.g., a press). A processor in communicationwith the crown may determine such motion is unintentional. Accordingly,the processor may reject (or ignore) the detected force, rather thanprocessing it as an input to the device.

An example tri-axial watch crown may include a stud or shaft whichattaches to, and protrudes outward from, the housing. A crown cap may beattached to the stud in order to provide a surface through which a userinteracts with the crown. A compliant material may be disposed betweenthe crown cap and the stud, facilitating motion of the cap relative tothe stud in the x, y, and z directions.

A force or displacement sensor may be placed within, or in contact with,the compliant material. Thus, if a user presses on the crown cap, thecompliant material may be compressed or otherwise deformed, causing thesensor to detect a motion of the crown cap relative to the stud. Thesensor may include a series of displacement or force sensors arrangedwithin the compliant material in such a way as to allow a processingunit to distinguish motions along the x-, y- and z-axes, or anycombination thereof. The processing unit may additionally correlate thedetected forces to an input to the electronic device.

In other examples, the compliant material may be omitted and/or thesensors may be in different locations. For example, a shaft may passinto the housing. Sensors may be arranged around the shaft and withinthe housing such that the sensors may detect motion of the shaftrelative to the housing.

In many embodiments, the crown may be rotatable. Rotation of the crownmay be detectable by the same or additional sensors as those whichdetect force applied to the crown. For example, the crown may include ashaft which may rotate relative to the housing of the watch. Sensors maydetect this rotation of the shaft relative to the housing. In otherexamples, the crown may include a stud rigidly attached to the housingand a crown cap may rotate around the stud. Sensors within the crown capand/or stud may detect the rotation of the crown cap.

In still other examples, the crown cap or shaft may only partiallyrotate. For example, a compliant material between a stud and a watchcrown may facilitate less than complete rotation of the crown relativeto the stud. The rotation may compress the compliant material, and forcesensors may detect a rotational force. The degree of rotation may bedetermined based on the amount of force detected by the force sensors.

These and other embodiments are discussed below with reference to FIGS.1-9. However, those skilled in the art will readily appreciate that thedetailed description given herein with respect to these figures is forexplanatory purposes only and should not be construed as limiting.

FIG. 1 depicts an electronic device in the form of a touch-enabledwatch, incorporating an example watch crown according to the presentdisclosure. The electronic device 100 includes a housing 108 surroundinga touch-enabled display 106. The display 106 may be configured todisplay indicia to a user and receive touch inputs. The electronicdevice may be operable to receive additional input from a user, such asthrough a button 104.

The electronic device 100 may also be operable to perform variousactions in response to input received via a watch crown 102 or similarinput structure. The watch crown 102 may receive inputs along threeaxes, such that it may move laterally with respect to the housing 108 inmultiple directions, axially with respect to the housing (e.g., towardor away from the housing), and/or rotationally. In some embodiments, thewatch crown 102 may further receive rotational inputs. Exampleembodiments of the watch crown 102 and its operation are furtherdescribed below with respect to FIGS. 2-8.

The electronic device 100 may detect and distinguish various directionalforce inputs to the watch crown 102. The electronic device 100 mayfurther detect, estimate, or otherwise measure an amount of the forceapplied to the watch crown 102. The electronic device 100 may include aprocessing unit, a memory, and other components, such as described withrespect to FIG. 9, to facilitate detecting, processing and responding toinputs received by the watch crown 102.

A compressible seal or structure (examples of which are shown in FIGS. 2and 6-8) may be positioned between the watch crown 102 and the housing108 and resist passage of contaminants into internal portions of thewatch crown 102 and/or the electronic device 100. Portions of thecompressible seal may collapse and/or bend to allow translationalmovement of the watch crown 102. The compressible seal may be configuredto obscure and/or otherwise block from view internal components of thewatch crown 102 and/or the electronic device 100. Such a configurationmay further allow use of internal components formed of differentmaterials and/or with different surfaces than the housing 108 and/orexternal portions of the watch crown 102 while preventing the internalcomponents from being visible from outside the housing 108.

The electronic device 100 is shown in FIG. 1 as a wearable electronicdevice having a touch-enabled display 106. However, it is understoodthat this is an example. In various implementations, the electronicdevice may be any kind of electronic device that utilizes a tri-axialinput mechanism such as the watch crown 102. Sample electronic devicesinclude a laptop computer, a desktop computer, a mobile computer, asmart phone, a tablet computer, a fitness monitor, a personal mediaplayer, a display, audiovisual equipment, and so on.

FIG. 2 depicts a cross-section of an example embodiment of a watch crowncoupled to the housing of the electronic device of FIG. 1, taken alongline A-A of FIG. 1. The watch crown 202 may be an input device whichincludes a stud 212 (e.g., a shaft) which couples to the housing 208 ofthe electronic device. The stud 212 also protrudes outward from thehousing 208. In some embodiments, the stud 212 is formed from a rigidmaterial, such as metal (e.g., aluminum, steel, copper, brass, etc.),plastic, glass, acrylic, ceramic, composites, other materials, orcombinations of materials.

The stud 212 may couple to a crown cap 210 (e.g., a cap). The crown cap210 may provide an input surface for user interaction. For example, thewatch crown 202 may displace in three directions: along the x-axis;along the y-axis; and along an axis of rotation defined by the z-axis.Displacement along the x or y axes is referred to as “lateral movement,”insofar as the watch crown 202 moves laterally with respect to thehousing 208. Displacement along the z axis is referred to as “axialmovement,” encompassing the watch crown 202 moving toward or away fromthe housing 208. In some embodiments, the watch crown 202 may furtherreceive rotational inputs via the crown cap 210.

The watch crown 202 may further include a sensor to detect anddistinguish forces applied to the crown cap 210 and/or displacement ofthe crown cap 210 relative to the stud 212. For example, one or morecapacitive force sensors may be formed using an insulating substrate 220between a flexible drive circuit 216 and a parallel flexible sensecircuit 218. In certain embodiments, the flexible drive circuit 216 iscoupled to a surface of the insulating substrate 220, and the flexiblesense circuit 218 is coupled to an opposite surface of the insulatingsubstrate 220. An electrode may be formed in the flexible drive circuit216 with a matching electrode formed in the flexible sense circuit 218.A capacitance may be formed across the matched pair of electrodes, andas force is applied to the crown cap 210, the insulating substrate 220between the electrodes may be compressed, resulting in a change incapacitance across the electrodes. A processing unit may determine anamount of force (generally from one or more force values) applied to thecrown cap 210 based on this change in capacitance detected by the forcesensor.

A “force value” may be an amount of force, or may be a component (suchas a vector) of a force input, detected by a force sensor. Typically, anembodiment may contain multiple force sensors, and different forcesensors may detect different force values. For example, one force sensormay detect a force value along an x axis, while another force sensor maydetect a force value along a y axis, and yet another force sensor maydetect a force value along a z axis. The various force values may beanalyzed by a processor to determine, estimate, correlate, or otherwisearrive at a force input applied to the watch crown 202, and typicallythe crown cap 210. Force values may be detected by any suitable forcesensor and need not be vectors of a force input, although this can bethe case in many embodiments.

The flexible drive circuit 216 and the flexible sense circuit 218 may beformed as a flexible printed circuit board or a similar structure. Aflexible printed circuit board may include a flexible substrate formedfrom a suitable material, such as polyimide or polyethyleneterephthalate. The flexible printed circuit board may further includeconductive material formed as one or more electrodes and one or morewires, traces, or similar conducting paths. The conductive material mayinclude materials such as silver, copper, gold, constantan, karma,isoelastic materials, indium tin oxide, or any combination thereof.

The insulating substrate 220 may be an electrically insulatingsubstrate, such as a dielectric. The insulating substrate 220 may beformed from a compressible material, such as a compliant foam, asilicone gel, and similar materials. The flexible drive circuit 216 andthe flexible sense circuit 218 may be coupled to the insulatingsubstrate 220 through an adhesive (e.g., a pressure sensitive adhesive)or similar technique.

The flexible drive circuit 216 and flexible sense circuit 218 mayinclude multiple sets of electrodes forming multiple force sensors. Withtwo or more force sensors implemented, the processing unit may detectand distinguish between forces applied along the three different axes,as discussed further below with respect to FIGS. 5A-5C.

In certain embodiments, the stud 212 is coupled to the housing 208 by afastener 222 (e.g., a clip, threaded nut, or similar fastener) which mayhold the stud 212 rigid with respect to the housing 208 along the x-,y-, and z-axes. The fastener 222 may encircle the stud 212 and mayadditionally threadedly engage the stud 212. Generally, the stud 212 iscoupled in a manner that prevents rotation about the z-axis.

The flexible drive circuit 216, flexible sense circuit 218, andinsulating substrate 220 may be placed between the stud 212 and thecrown cap 210, and surrounded by a compliant material 214. The compliantmaterial 214 may facilitate movement of the crown cap 210 relative tothe stud 212 under an exerted force, while providing a restoring forceto return the crown cap 210 once the force is released. In addition, thecompliant material 214 may facilitate compression of the insulatingsubstrate 220, in order to transmit an applied force to the flexibledrive circuit 216 and flexible sense circuit 218.

The compliant material 214 may be formed from a suitable material, suchas silicone, polyurethane, polyvinylchloride, rubber, fluoroelastomer,another polymer, or similar material. The compliant material 214 may beinjection molded to the stud 212 and/or the crown cap 210, or may bebonded to the stud 212 and the crown cap 210 in another suitable manner.

In some embodiments, the watch crown 202 may prevent or reduce entry ofwater, dust, or other contaminants to the housing 208. Accordingly, agasket 228 (such as a silicone or a rubber gasket) may be coupled to thecrown cap 210 or the housing 208 at the edge of the crown cap 210 toprevent entry of contaminants. A lubricant 226 (e.g., electrical grease,silicone gel, or similar material) may further prevent entry ofcontaminants to the housing 208. Each of the gasket 228 and thelubricant 226 may allow the crown cap 210 to displace relative to thestud 212, while resisting the entry of contaminants between the housing208 and the crown cap 210.

Additionally, a pressure seal may be formed between the stud 212 and thehousing 208 to further prevent liquid or other contaminants fromentering the housing 208. The stud 212 and/or housing 208 may include adepression to house an O-ring 224 (or similar water sealing element) toprovide the pressure seal, resisting the entry of liquids or othercontaminants even under pressure.

As depicted in FIG. 2, the stud 212 may be at least partially hollow.The hollow portion of the stud 212 may provide a path to route theflexible drive circuit 216 and the flexible sense circuit 218 from theregion between the stud 212 and the crown cap 210 to within the housing208. An opening 217 may be defined in the stud through which theflexible drive circuit 216 and the flexible sense circuit 218 may berouted from the region between the stud 212 and the crown cap 210 to thehollow portion of the stud 212. The opening 217 and the hollow portionof the stud 212 may typically be filled with the same compliant material214, sealing the crown cap 210 to the stud 212, as well as sealing thehollow portion of the stud 212, which may also prevent or reduce entryof contaminants to the housing.

The opening 217 may facilitate an electrical connection between one ormore force sensors and a processing unit within the housing 208. Forexample, the flexible drive circuit 216 and the flexible sense circuit218 may include conductive material (e.g., wires, conductive traces)which forms an electrical connection to force sensors. The flexibledrive circuit 216 and flexible sense circuit 218 may also beelectrically connected to the processing unit (e.g., directly or byconnecting to electrical circuitry connecting to the processing unit).

In many embodiments, the opening 217 may be positioned on a sideadjacent an end of the stud 212, which may facilitate sealing with thecompliant material 214 surrounding the stud 212. In other embodiments,the opening 217 may be positioned differently, such as at the end of thestud 212 of further from the end. The opening 217 may be formed in anappropriate shape, such as a round opening, a rectangular opening, oranother geometric shape (including a non-regular geometric shape). Thecross-section of the opening 217 may change in size and/or shape alongthe wall of the stud 212, or it may have a regular size and/or shape. Insome examples, more than one opening may be defined in the stud 212(e.g., to facilitate connection of additional sensors to the processingunit).

FIG. 3 depicts a partial cross-section of a watch crown (e.g., inputdevice), similar to the depiction in FIG. 2, illustrating only a studand one or more force sensors, while omitting other components of thewatch crown, such as the crown cap 210 and compliant material 214depicted in FIG. 2. As discussed above with respect to FIG. 2, in someembodiments the stud 312 is rigid, formed from a metal, plastic,ceramic, or similar material. The stud 312 may be formed with a threadedinternal portion 311 and a protruding portion 313 separated by a flange315. The flange 315 may define a depression (e.g., an annular or partialgroove) to house an O-ring (such as O-ring 224, depicted in FIG. 2)adjacent the internal portion 311.

The internal portion 311 of the stud 312 may be hollow, to provide apath to route the flexible drive circuit 316 and the flexible sensecircuit 318 from the region between the stud 312 and the crown cap towithin the housing (e.g., to be electrically coupled to a processingunit or other circuitry). In many embodiments, an opening 317, such asan aperture, is formed through the protruding portion 313 of the stud312 adjacent the flange 315, through which the flexible drive circuit316 and the flexible sense circuit 318 may pass from the region betweenthe stud 312 and the crown cap into the hollow internal portion 311 ofthe stud 312.

The flexible drive circuit 316 and the flexible sense circuit 318 mayform multiple force sensing pixels (pairs of capacitive electrodes)around the protruding portion 313 of the stud 312 (such as furtherdepicted below with respect to FIGS. 5A-5C). The flexible drive circuit316 and/or the flexible sense circuit 318 may be shaped in a C-shapealong the protruding portion 313 as depicted, or each may form a ring orpartial ring around the protruding portion 313.

In some embodiments, the flexible sense circuit 318 may be coupled tothe protruding portion 313 of the stud 312 by an adhesive (e.g., apressure sensitive adhesive) or similar technique. The stud 312 mayaccordingly provide a resistive force against compression of theinsulating substrate 320 through coupling across the flexible sensecircuit 318. In other embodiments, the flexible sense circuit 318 maynot be coupled to the stud 312, but the flexible drive circuit 316 andthe flexible sense circuit 318 may instead be surrounded (e.g.,encompassed) by a compliant material (such as the compliant material 214depicted in FIG. 2).

Turning to FIGS. 4A-4D, the operation of the flexible drive circuit andthe flexible sense circuit is further illustrated as force is applied tothe crown cap. FIGS. 4A-4D depict sample cross-sections of the watchcrown 402, similar to the depiction in FIG. 2, illustrating the stud412, the crown cap 410, and one or more force sensors formed by theflexible drive circuit 416 and the flexible sense circuit 418 coupled tothe insulating substrate 420. Additional components, such as a compliantmaterial between the crown cap 410 and the stud 412, are omitted forclarity.

FIG. 4A illustrates the watch crown 402 at a first position (e.g., aresting position), in which no force is applied to the crown cap 410.Compliant material 414 is positioned between the crown cap 410 and thestud 412. The compliant material 414 facilitates displacement of thecrown cap 410 when a force is applied, while providing a restoring forceto return the crown cap 410 to its resting position when the force isreleased, and generally has the same properties and function ascompliant material 214 described above with respect to FIG. 2.

FIG. 4B depicts the watch crown 402 in a second position, in response toa user's application of an axial force F (e.g., a force along thez-axis) to the crown cap 410. The applied force F may compress thecompliant material 414 positioned around point A (e.g., along the end ofthe stud 412 adjacent the crown cap 410). This compression of thesubstrate in turn causes the insulating substrate 420 (e.g.,electrically insulating substrate) to compress around point A. As theinsulating substrate 420 around point A is compressed, the flexiblesense circuit 418 and the flexible drive circuit 416 move closertogether at point A, and a force sensor 434 detects the compressiveforce.

A processing unit may determine, based on the force detected by theforce sensor 434, that the crown cap 410 has moved along the z-axis(e.g., by comparing the force detected by the force sensor 434 withother force sensors in the flexible drive circuit 416 and the flexiblesense circuit 418). The processing unit may further correlate orotherwise associate the force detected with a particular type of input.For example, the axial motion of FIG. 4C may be correlated with a buttoninput, such as selection of an item or the start of a timer. The amountof compressive force F applied along the z-axis may also be detected,and different inputs may correspond to varying amounts of force (e.g.,force values) detected by the force sensor 434.

In another example, a user may apply a lateral force F (e.g., a forcealong the y-axis) to the crown cap 410, as depicted in FIG. 4C. Theforce F may cause the crown cap 410 to move downward relative to thestud 412, compressing the compliant material 414 around point B andplacing the compliant material around point C in tension. This may inturn compress the insulating substrate 420 around point B and place theinsulating substrate 420 around point C in tension.

In response, the flexible sense circuit 418 and the flexible drivecircuit 416 move closer together at point B, and a force sensor 436detects the compressive force. In addition, the flexible sense circuit418 and the flexible drive circuit 416 move apart at point C, and aforce sensor 438 detects the tension.

In another example, as depicted in FIG. 4D, a user may apply a force Fto the crown cap 410 at an oblique angle (e.g., an angle which is alonga direction between a lateral and axial direction). The force F maycause the crown cap 410 to tilt, compressing the compliant material 414around point D and placing the compliant material around point E intension.

In some embodiments, the material properties of the compliant material414 may cause the crown cap 410 to tilt rather than translate along they-axis in response to a lateral force F′. For example, the compliantmaterial 414 may resist compression immediately above the stud 412,while allowing compression within the compliant material 414 aroundpoint D (e.g., adjacent the end of the stud 412). Thus, the compressiveforce applied along the y-axis may be transferred to compress thecompliant material 414 around point D while placing the compliantmaterial 414 around point E in tension. Accordingly, the crown cap 410may tilt rather than translate laterally in response to force along they-axis.

As the compliant material 414 around point D compresses, the insulatingsubstrate 420 around point D is also compressed. As the insulatingsubstrate 420 around point D is compressed, the flexible sense circuit418 and the flexible drive circuit 416 move closer together at point D,and a first force sensor 432 detects the compressive force.

Simultaneous with the compression around point D, the compliant materialaround point D may expand (e.g., be placed under tension), placing theinsulating substrate 420 in tension. As the insulating substrate 420around point D is placed in tension, the flexible sense circuit 418 andthe flexible drive circuit 416 move apart at point D, and a second forcesensor 430 detects the tension.

The processing unit may compare the compressive force detected by thefirst force sensor 432 and the tension detected by the second forcesensor 430 to determine that the crown cap 410 has tilted with respectto the stud 412. The processing unit may further determine the relativeamounts of force (e.g., after determining force values corresponding toeach respective force sensor 430, 432) or tension measured by the firstforce sensor 432 and the second force sensor 430 to determine a profileof the type of force applied to the crown cap 410.

Turning to FIG. 4E, a rotation of the watch crown 402 may be detected,even in embodiments in which the stud 412 is coupled to the watchhousing in a manner that prevents rotation of the stud 412. In suchembodiments the crown cap 410 may be partially rotatable with respect tothe stud 412. For example, the compliant material 414 between the crowncap 410 and the stud 412 may allow some, but not complete, rotation ofthe crown cap 410 about the stud 412.

A user may apply a rotational force F (e.g., a force involving arevolution about the z-axis) to the crown cap 410, which causes thecompliant material 414 to deform in shear about the z-axis. For example,the compliant material 414 around point B and around point C may beplaced under tension and/or compression. As the compliant material 414deforms, the flexible drive circuit 416 around points B and C maytranslate about the z-axis relative to the flexible sense circuit 418.Accordingly, a pair of electrodes in the force sensor 436 at the top ofthe stud 412 may translate away from each other about the Z-axis,causing a change in capacitance to be measured by the force sensor 436.Another pair of electrodes in the force sensor 438 at the bottom of thestud may translate along the same rotational direction, causing a changein capacitance to be measured by the force sensor 438.

The processing unit may compare the rotational force detected by theforce sensor 436 at the top of the stud 412 with the rotational forcedetected by the force sensor 438 at the bottom of the stud 412 todetermine that the crown cap 410 has rotated in a particular direction(e.g., clockwise or counter-clockwise) with respect to the stud 412. Forexample, the electrodes of the force sensor 436 at the top of the stud412 may be offset such that a clockwise rotation increases thecapacitance of the force sensor 436 (due to bringing more of theelectrodes in parallel) and a counter-clockwise rotation decreasescapacitance of the force sensor 436 (due to separating the electrodes).In some examples, changes in other force sensors may also be analyzed todistinguish a rotation from a lateral force or other input. Theprocessing unit may further determine an amount of rotational forceapplied to the crown cap 410, which may be interpreted as an intendeddegree of input rotation.

In some examples, the force sensors 430, 432, 434, 436, 438 may detectforce inputs along more than one of the x-, y-, and z-axes. Theprocessor may analyze multiple force sensing signals to determine thedirections and amounts of such multi-axial forces. The processor mayfurther compare these force sensing signals to input profiles orotherwise determine an intended type of input to the watch crown 402.For example, the electronic device may be a watch on a user's wrist. Insuch an embodiment, accidental button presses may occur as a user'swrist moves. The processing unit may receive, from one or more forcesensors, force inputs along both the y-axis and the z-axis, or as a tiltsimilar to FIG. 4D. The processing unit may further determine (e.g., bycomparing the force inputs to an input profile or the like) that such aninput is unintended, and reject it as a user input. As one example, ifthe watch crown 402 tilts, the input may be rejected.

In many embodiments, the processing unit may distinguish between thevarious movements of the watch crown 402 initiated in response to userforce. The processing unit may further interpret (e.g., correlate) themovements as distinct inputs for different operations of the electronicdevice. For example, a first lateral movement (movement along they-axis) may adjust a brightness or volume associated with the electronicdevice, while a second lateral movement (movement along the x-axis) mayswitch the device between a silent mode and an alert mode.

A rotational movement (movement about the z-axis) may cause theelectronic device to scroll between a list of available softwareapplication for selection, while an axial movement (movement along thez-axis) may select the software application or start a timer. Inaddition, movements along multiple directions may be processeddifferently. Force inputs may be compared with one or more forceprofiles, which may correspond to a particular type of input to thecrown cap 410. For example, the lateral force input of FIG. 4C may betreated as a volume change, the rotational input of FIG. 4E may change agraphical display (e.g., by moving a selection indicator), the axialforce input of FIG. 4B is treated as a selection, and the tilt input ofFIG. 4D is treated as a display brightness change.

It should be understood that the various inputs are adaptable to userpreferences and context, and the above examples are illustrative innature. For example, the electronic device may operate various softwareapplications, and how each type of watch crown 402 movement may beinterpreted may be based on an active software application. Generally,the examples given herein are but some sample ways in which an input tothe crown may change an indicium (or indicia) displayed by theelectronic device. As used herein, an “indicium” is any text, graphic,icon, symbol, or the like, Sample indicia include application icons,volume indicators, brightness indicators, data shown in a list, powerindicators, words, numbers, and so on. “Indicia” is the plural of“indicium.”

FIGS. 5A-5C depict various potential arrangements for capacitiveelectrodes (e.g., force sensors) for sensing forces applied to a watchcrown. The capacitive electrodes 516 a-516 j, 518 a-518 j may be formedon or within flexible circuits (such as flexible drive circuit 216 andflexible sense circuit 218 as depicted in FIG. 2), and are shown inFIGS. 5A-5C without such encapsulation for illustrative purposes.Likewise, FIGS. 5A-5C omit compliant material, such as compliantmaterial 214 depicted in FIG. 2, for clarity.

As discussed above, amounts of force applied to the watch crown 502 maybe detected by one or more force sensors positioned between the crowncap 510 and the stud 512. The force sensors may be formed from one ormore matched pairs of capacitive electrodes 516 a-516 j, 518 a-518 jcoupled to an insulating substrate (such insulating substrate 220 asdepicted in FIG. 2, omitted from FIGS. 5A-5C for illustrative purposes).The force sensors may be arranged in various manners to facilitatedetection of various inputs, such as depicted above with respect toFIGS. 4A-4D.

For example, FIG. 5A depicts a watch crown 502 having two force sensors.A first force sensor includes a drive electrode 516 a and a senseelectrode 518A positioned at the top of the stud 512. A second forcesensor includes a drive electrode 516 b and a sense electrode 518 bpositioned at the bottom of the stud 512.

In operation, a charge may be placed on the first drive electrode 516 a,and a capacitance across the first drive electrode 516 a and the firstsense electrode 518 a may be monitored. As a force is applied to thecrown cap 510, the distance between the first drive electrode 516 a andthe first sense electrode 518 a may change, resulting in the capacitancebetween the electrodes exhibiting a corresponding change. The change incapacitance may be interpreted by a processing unit as an amount offorce (e.g., one or more force values) applied to the crown cap. Eachforce sensor may operate in a similar manner.

As depicted in FIG. 5A, the drive electrode 516 a, 516 b in one or bothforce sensors may be offset from the corresponding sense electrode 518a, 518 b. Because of this offset, the capacitance may change in distinctmanners for distinct force inputs. For example, a force downward (alongthe y-axis) may increase a detected capacitance at the force sensorabove the stud 512 (drive electrode 516 a and sense electrode 518 a),while decreasing a detected capacitance at the force sensor below thestud 512 (drive electrode 516 a and sense electrode 518 a). A forcetoward the stud 512 along the z-axis decreases the detected capacitanceat both force sensors.

A force along a particular axis may cause an increase or a decrease incapacitance at each force sensor (represented by pairs of driveelectrodes and sense electrodes). The below table illustrates how aforce along each direction may cause the measured capacitance of eachforce sensor to increase (+) or decrease (−). It should be understoodthat the magnitude of capacitance change may vary between each forcesensor even where the two sensors increase or two sensors decrease.

Force direction 516a, 518a 516b, 518b X+ − − X− − − Y+ − + Y− + − Z+ + +Z− − −

The table above illustrates the X+, X−, and Z− directions as all havingsimilar responses in the force sensors. Accordingly, in many embodimentsat least one additional force sensor (not depicted in the cross-sectionof FIG. 5A) may be configured to distinguish force along the x-axis. Forexample, a force sensor may be positioned behind the stud 512 whichdetects an increased capacitance in response to force along the X+direction and a decreased capacitance in response to force along the X−direction. Another force sensor may be positioned in front of the stud512 which has the reverse response to forces along the x-axis.

In other embodiments, the watch crown 502 may include additional forcesensors, or the force sensors may be arranged differently. For example,as depicted in FIG. 5B, a first force sensor may be formed from a firstdrive electrode 516 c and a first sense electrode 518 c positioned atthe top of the stud 512. Another force sensor may be formed from asecond drive electrode 516 d and a second sense electrode 518 dpositioned at the protruding end of the stud 512. Similar to thearrangement of FIG. 5A, the force sensors depicted in FIG. 5B may bepositioned to distinguish between force inputs along differentdirections, in which capacitance may increase as the electrodes in aforce sensor move together or the overlapping plate area increases, andcapacitance may decrease as the electrodes in a force sensor move apartor the overlapping plate area decreases.

The below table illustrates how a force along each direction may causethe measured capacitance of each force sensor to increase (+) ordecrease (−).

Force direction 516c, 518c 516d, 518d X+ − − X− − − Y+ − − Y− + − Z+ − −Z− − +

The table above illustrates the X+, X−, and Z− directions as all havingsimilar responses in the force sensors. Accordingly, in many embodimentsat least one additional force sensor (not depicted in the cross-sectionof FIG. 5B) may be configured to distinguish force along the x-axis. Forexample, a force sensor may be positioned behind the stud 512 whichdetects an increased capacitance in response to force along the X+direction and a decreased capacitance in response to force along the X−direction. Another force sensor may be positioned in front of the stud512 which has the reverse response to forces along the x-axis.

As depicted in FIG. 5C, additional force sensors may be included in awatch crown 502 to provide additional data points available to registerand interpret a force input to the watch crown 502. For example, forcesensors may be formed between a first drive electrode 516 e and a firstsense electrode 518 e; between a second drive electrode 516 f and asecond sense electrode 518 f; between a third drive electrode 516 g anda third sense electrode 518 g; between a fourth drive electrode 516 hand a fourth sense electrode 518 h; and between a fifth drive electrode516 j and a fifth sense electrode 518 j.

The below table illustrates how a force along each direction may causethe measured capacitance of each force sensor to increase (+) ordecrease (−).

Force direction 516e, 518e 5161, 518b1 516g, 518g 516h, 518h 516j, 518jX+ − − − − − X− − − − − − Y+ − − − − + Y− + − − − − Z+ − − − − − Z−− + + + −

The table above illustrates the X+, X−, and Z− directions as all havingsimilar responses in the force sensors. Accordingly, in many embodimentsat least one additional force sensor (not depicted in the cross-sectionof FIG. 5C) may be configured to distinguish force along the x-axis. Forexample, a force sensor may be positioned behind the stud 512 whichdetects an increased capacitance in response to force along the X+direction and a decreased capacitance in response to force along the X−direction. Another force sensor may be positioned in front of the stud512 which has the reverse response to forces along the x-axis.

The multiple force sensors depicted in FIG. 5C along the end of the stud512 (e.g., formed by drive electrodes 516 f, 516 g, 516 h and senseelectrodes 518 f, 518 g, 518 h) may further facilitate distinguishingforces at oblique angles, such as forces causing a tilt as depicted inFIG. 4D. In some embodiments, additional force sensors may be includedaround the stud 512 to distinguish force inputs along additionaldirections and further clarify the direction of force being detected.

In many embodiments, a processing unit correlates an amount of forceexerted on the crown cap 510 with changes in capacitance at one or moreforce sensors. The changes in capacitance may thus be expressed with agiven magnitude and signed value. Generally, a positive value indicatesan increase in capacitance, and a negative value indicates a decrease incapacitance. The processing unit may compare the magnitude and sign ofchanges at each pixel, along with a known location of each pixel, inorder to determine a vector representing the magnitude andthree-dimensional direction of an input to the watch crown 502. Theaccuracy of the determined vector may depend on the location and numberof force sensors, with an increased number of force sensors generallyyielding a more accurate determination.

In some embodiments, the capacitance measurements of the force sensorsmay be processed in other ways in order to determine an input to thewatch crown 502 based on the measurements. For example, the processingunit may be coupled to a memory storing input profiles, in which themeasured changes in capacitance may be compared to the input profiles todetermine a type of user input.

FIGS. 2-5C have been discussed generally with reference to detecting aforce applied to the watch crown using capacitive force sensingelements. It should be understood that embodiments of the presentdisclosure may incorporate other force or displacement sensing elementsto achieve similar aims. For example, each force sensor may be formedusing a strain gauge, a piezoelectric sensor, a force-sensitiveresistor, and similar force or displacement sensing elements.Accordingly, discussion of force sensors with reference to capacitiveforce sensing are illustrative in nature and would apply similarly toother force or displacement sensing elements.

FIG. 6 depicts a cross-section of another example embodiment of a watchcrown coupled to the housing of the electronic device of FIG. 1, takenalong line A-A of FIG. 1. The watch crown 602 includes a shaft 640 whichrotatably couples to the housing 608 of the electronic device. The shaft640 extends outward from the housing 608 and couples to a crown cap 610.In some embodiments, the shaft 640 and/or crown cap 610 are formed froma rigid material, such as metal (e.g., aluminum, steel, copper, brass,etc.), plastic, glass, acrylic, ceramic, other materials, orcombinations of materials. In some embodiments, the shaft 640 and crowncap 610 are integrally formed, while in other embodiments they may beseparately formed and coupled together.

The crown cap 610 may provide an input surface for user interaction. Forexample, the watch crown 602 may facilitate displacement to the watchcrown 602 along three axes: the x-axis (lateral in a first directionrelative to the shaft 640), the y-axis (lateral in a second directionrelative to the shaft 640), and the z-axis (axially, or along the axisof the shaft 640). For example, a series of force sensors 654 a, 654 b,654 c may be placed on or around an internal portion of the shaft 640.The force sensors 654 a, 654 b, 654 c may detect an amount and directionof force applied to the crown cap 610, as translated to the end of theshaft 640. For example, the force sensors 654 a, 654 b, 654 c may deformin response to movements of the shaft 640 in a manner similar to theforce sensors depicted in FIGS. 4A-5C.

Generally, the crown cap 602 and the shaft 640 may also receiverotational inputs. For example, the shaft 640 may be a rotatable shaftand rotational input to the watch crown 602 may be detected bypositional sensors 650 a, 650 b. In some embodiments, positional sensors650 a, 650 b may be coupled to the housing 608 adjacent the crown cap610. The positional sensors 650 a, 650 b may detect the rotationalposition of the crown cap by detecting the location of one or moreelectrodes 652 a, 652 b or other positional indicators on the crown cap610. The positional sensors 650 a, 650 b may operate by capacitivesensing, optical sensing, strain sensing, or similar techniques. Anumber of positional sensors 650 a, 650 b and/or electrodes (positionalindicators) 652 a, 652 b may be included in the watch crown 602 toenable detection of the rotational position of the crown cap 610, andmay additionally enable a determination of the speed, acceleration, andsimilar attributes of rotational inputs.

A processing unit coupled to the positional sensors 650 a, 650 b maydetermine an amount of movement, speed, acceleration, and/or otherattributes of rotational inputs. In some embodiments, the processingunit may determine whether an amount of rotation exceeds a threshold,and may register an input (e.g., scrolling through a list of items, orotherwise changing an indicium on the display) once the amount ofrotation exceeds the threshold.

In many embodiments, the shaft 640 is coupled to the housing 608 by aretaining clip 622, or similar fastener, which may retain the end of theshaft 640 within the housing 608, while allowing the shaft 640 to rotateabout the z-axis, and be displaced slightly along the x-, y-, andz-axes. In some embodiments, a compliant material (omitted from FIG. 6for clarity) may surround all or a portion of the shaft. The compliantmaterial may facilitate a transfer of force from the shaft 640 to theforce sensors 654 a, 654 b, 654 c. The watch crown may includeadditional elements, such as an O-ring 624, which may be similar toelements depicted in FIG. 2.

FIG. 7 depicts a cross-section of another example embodiment of a watchcrown coupled to the housing of the electronic device of FIG. 1, takenalong line A-A of FIG. 1. The watch crown 702 may be similar to thewatch crown 202 depicted in FIG. 2. Here, the crown cap 710 may coupleto a protrusion 742 from the housing 708 of the electronic device. Insome embodiments, the protrusion 742 is formed integrally with thehousing 708, while in other embodiments the protrusion 742 is formedseparately and coupled to the housing 708.

Similar to the watch crown 202 of FIG. 2, a compliant material 746 maybe placed between the crown cap 710 and the protrusion 742 to facilitatedisplacement of the crown cap 710 along the x-, y-, and z-axes, and mayalso facilitate partial rotation of the crown cap 710. The watch crown702 may also include a gasket 744 (such as a silicone or a rubbergasket) coupled to the crown cap 710 and/or the housing 708 at the edgeof the crown cap 710 to prevent entry of contaminants.

The watch crown 702 may further include force sensors, such as a seriesof capacitive force sensors (similar to the force sensors described withrespect to FIGS. 4A-5C) formed using drive electrodes 716 a, 716 b, 716c coupled to the crown cap 710 and corresponding sense electrodes 718 a,718 b, 718 c coupled to the protrusion 742. As force is applied to thecrown cap 710, the compliant material 746 between the first driveelectrode 716 a and the first sense electrode 718 a may be compressed,resulting in a change in capacitance across the first drive electrode716 a and the first sense electrode 718 a.

FIG. 8 depicts a cross-section of another example embodiment of a watchcrown coupled to the housing of the electronic device of FIG. 1, takenalong line A-A of FIG. 1. The watch crown 702 may be similar to thewatch crown 202 depicted in FIG. 2, the watch crown 602 depicted in FIG.6, and/or the watch crown 702 depicted in FIG. 7. The watch crown 802includes a shaft 840 which rotatably couples to the housing 808 of theelectronic device. The shaft 840 extends outward from the housing 808into a flared end 848 and couples to a crown cap 810. The watch crown802 may also include an O-ring 824 housed within a depression of thehousing 808 and/or the shaft 840.

A compliant material 846 may be placed between the crown cap 810 and theflared end 848 of the shaft 840 to facilitate displacement of the crowncap 810 along the x-, y-, and z-axes. A series of capacitive forcesensors may be formed using drive electrodes 816 a, 816 b, 816 c coupledto the crown cap 810 and corresponding sense electrodes 818 a, 818 b,818 c coupled to the flared end 848 of the shaft 840.

The watch crown 802 may further receive rotational inputs to the crowncap 810, causing the shaft 840 to rotate about the z-axis. One or morepositional sensors 850 may be coupled to the housing 808 adjacent thecrown cap 810. The positional sensor 850 may detect a rotationalposition of the crown cap 810 by detecting the location of one or moreelectrodes 852 or other positional indicators on the crown cap 810.

FIGS. 9A-11B generally depict examples of manipulating graphicsdisplayed on an electronic device through inputs provided by forceand/or rotational inputs to a crown of the device. This manipulation(e.g., selection, acknowledgement, motion, dismissal, magnification, andso on) of a graphic may result in changes in operation of the electronicdevice and/or graphics displayed by the electronic device. Althoughspecific examples are provided and discussed, many operations may beperformed by rotating and/or applying force to a crown such as theexamples described above. Accordingly, the following discussion is byway of example and not limitation.

FIG. 9A depicts an example electronic device 900 (shown here as anelectronic watch) having a watch crown 902. The watch crown 902 may besimilar to the examples described above, and may receive force inputsalong a first lateral direction, a second lateral direction, or an axialdirection of the watch crown. The watch crown 902 may also receiverotational inputs. A display 906 shows information and/or othergraphics. In the current example, the display 906 depicts a list ofvarious items 961, 962, 963, all of which are example indicia.

FIG. 9B illustrates how the graphics shown on the display 906 change asthe watch crown 902 rotates, partially or completely (as indicated bythe arrow 960). Rotating the watch crown 902 causes the list to scrollor otherwise move on the screen, such that the first item 961 is nolonger displayed, the second and third items 962, 963 each move upwardson the display, and a fourth item 964 is now shown at the bottom of thedisplay. This is one example of a scrolling operation that can beexecuted by rotating the watch crown 902. Such scrolling operations mayprovide a simple and efficient way to depict multiple items relativelyquickly and in sequential order. A speed of the scrolling operation maybe controlled by the amount of rotational force applied to the watchcrown 902 and/or the speed at which the watch crown 902 is rotated.Faster or more forceful rotation may yield faster scrolling, whileslower or less forceful rotation yields slower scrolling. The watchcrown 902 may receive an axial force (e.g., a force inward toward thedisplay 906 or watch body) to select an item from the list, in certainembodiments.

FIGS. 10A and 10B illustrate an example zoom operation. The display 1006depicts a picture 1066 at a first magnification, shown in FIG. 10A; thepicture 1066 is yet another example of an indicium. A user may apply alateral force (e.g., a force along the x-axis) to the watch crown 1002of the electronic device 1000 (illustrated by arrow 1065), and inresponse the display may zoom into the picture 1066, such that a portion1067 of the picture is shown at an increased magnification. This isshown in FIG. 10B. The direction of zoom (in vs. out) and speed of zoom,or location of zoom, may be controlled through force applied to thewatch crown 1002, and particularly through the direction of appliedforce and/or magnitude of applied force. Applying force to the watchcrown 1002 in a first direction may zoom in, while applying force to thewatch crown 1002 in an opposite direction may zoom out. Alternately,rotating or applying force to the watch crown 1002 in a first directionmay change the portion of the picture subject to the zoom effect. Insome embodiments, applying an axial force (e.g., a force along thez-axis) to the watch crown 1002 may toggle between different zoom modesor inputs (e.g., direction of zoom vs. portion of picture subject tozoom). In yet other embodiments, applying force to the watch crown 1002along another direction, such as along the y-axis, may return thepicture 1066 to the default magnification shown in FIG. 10A.

FIGS. 11A and 11B illustrate possible use of the watch crown 1102 tochange an operational state of the electronic device 1100 or otherwisetoggle between inputs. Turning first to FIG. 11A, the display 1106depicts a question 1168, namely, “Would you like directions?” As shownin FIG. 11B, a lateral force may be applied to the watch crown 1102(illustrated by arrow 1170) to answer the question. Applying force tothe watch crown 1102 provides an input interpreted by the electronicdevice 1100 as “yes,” and so “YES” is displayed as a graphic 1169 on thedisplay 1106. Applying force to the watch crown 1102 in an oppositedirection may provide a “no” input. Both the question 1168 and graphic1169 are examples of indicia.

In the embodiment shown in FIGS. 11A and 11B, the force applied to thewatch crown 1102 is used to directly provide the input, rather thanselect from options in a list (as discussed above with respect to FIGS.9A and 9B).

As mentioned previously, force or rotational input to a watch crown ofan electronic device may control many functions beyond those listedhere. The watch crown may receive distinct force or rotational inputs toadjust a volume of an electronic device, a brightness of a display, orother operational parameters of the device. A force or rotational inputapplied to the watch crown may rotate to turn a display on or off, orturn the device on or off. A force or rotational input to the crown maylaunch or terminate an application on the electronic device. Further,combinations of inputs to the watch crown may likewise initiate orcontrol any of the foregoing functions, as well.

FIG. 12 depicts example components of an electronic device in accordancewith the embodiments described herein. The schematic representationdepicted in FIG. 12 may correspond to components of the devices depictedin FIGS. 1-11B, described above. However, FIG. 12 may also moregenerally represent other types of devices with a tri-axial inputmechanism similar to the watch crown described above.

As shown in FIG. 12, a device 1200 includes a processing unit 1280operatively connected to computer memory 1286. The processing unit 1280may be operatively connected to the memory 1286 via an electronic bus orbridge. The processing unit 1280 may include one or more computerprocessors or microcontrollers that are configured to perform operationsin response to computer-readable instructions. Additionally oralternatively, the processing unit 1280 may include other processorswithin the device 1200 including application specific integrated chips(ASIC) and other microcontroller devices. The processing unit 1280 maybe configured to perform functionality described in the examples above.

The memory 1286 may include a variety of types of non-transitorycomputer-readable storage media, including, for example, read accessmemory (RAM), read-only memory (ROM), erasable programmable memory(e.g., EPROM and EEPROM), or flash memory. The memory 1286 is configuredto store computer-readable instructions, sensor values, and otherpersistent software elements.

In this example, the processing unit 1280 is operable to readcomputer-readable instructions stored on the memory 1286. Thecomputer-readable instructions may adapt the processing unit 1280 toperform the operations or functions described above with respect toFIGS. 1-8. The computer-readable instructions may be provided as acomputer-program product, software application, or the like.

For example, the memory 1286 may store a plurality of input profiles,correlating a particular profile of force sensor measurements to aparticular input or type of input. Accordingly, when the processing unit1280 detects a force input to the watch crown or similar input device,the processing unit 1280 may compare the measurements of distinct forcesensors to the input profile. If the force measurements match an inputprofile, the force measurements may be correlated (e.g., associated)with a particular type of input and processed accordingly.

The device 1200 may include a display 1282 that is configured to rendervisual information generated by the processing unit 1280. The display1282 may include a liquid-crystal display (LCD), organic light emittingdiode (OLED) display, organic electroluminescent (OEL) display, or thelike. If the display 1282 is an LCD, the display may also include abacklight component that can be controlled to provide variable levels ofdisplay brightness. If the display 1282 is an OLED or OEL type display,the brightness of the display 1282 may be controlled by modifying theelectrical signals that are provided to display elements.

The device 1200 may also include a power source 1284, such as a battery,that is configured to provide electrical power to the components of thedevice 1200. The power source 1284 may include one or more power storagecells that are linked together to provide an internal supply ofelectrical power. The power source 1284 may be operatively coupled topower management circuitry that is configured to provide appropriatevoltage and power levels for individual components or groups ofcomponents within the device 1200. The power source 1284, via powermanagement circuitry, may be configured to receive power from anexternal source, such as an AC power outlet. The power source 1284 maystore received power so that the device 1200 may operate withoutconnection to an external power source for an extended period of time,which may range from several hours to several days.

In some embodiments, the device 1200 includes one or more input/outputcomponents 1290. The input/output component 1290 is a device that isconfigured to receive user input. The input/output component 1290 mayinclude, for example, a push button, a touch-activated button, or thelike. In some embodiments, the input/output components 1290 may providea dedicated or primary function, including, for example, a power button,volume buttons, home buttons, scroll wheels, and camera buttons.Generally, a force sensor and a positional sensor may also be classifiedas an input component. However, for purposes of this illustrativeexample, the force sensors 1288 and the positional sensors 1294 aredepicted as distinct components within the device 1200.

The device 1200 may also include one or more positional sensors 1294configured to determine a rotational position of a watch crown. Thepositional sensors 1294 may detect the rotational position of the crowncap by detecting the location of one or more electrodes or otherpositional indicators on the crown cap. The positional sensors 1294 mayoperate by capacitive sensing, optical sensing, or similar techniques.The positional sensors 1294 are coupled to the processing unit 1280which may determine the speed, acceleration, and similar attributes ofrotational inputs.

The device 1200 may also include one or more force sensors 1288 inaccordance with the embodiments described herein. As previouslydescribed, the force sensors 1288 may be configured to receive forceinput to the watch crown. In some embodiments, the force sensors 1288may be implemented in a pair of flexible circuits coupled to aninsulating substrate. In some embodiments, other force-sensitivestructures may be employed, such as a strain gauge, a piezoelectricsensor, a force sensitive resistor, and similar force sensing elements.

The device 1200 may also include a haptic device 1292. The haptic device1292 may be implemented with a number of devices and technologies, suchas an electromechanical actuator. The haptic device 1292 may becontrolled by the processing unit 1280, and may be configured to providehaptic feedback to a user interacting with the device 1200.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not intended to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings.

What is claimed is:
 1. A watch, comprising: a housing; a display atleast partially within the housing; a crown, comprising: a stud coupledto the housing and protruding from the housing; a crown cap coupled tothe stud; a compliant material surrounding at least a portion of thestud and at least partially surrounded by the crown cap, the compliantmaterial configured to deform in response to a movement of the crown caprelative to the stud caused by an input provided to the crown cap; aforce sensor positioned between the stud and the crown cap andconfigured to provide a signal in response to a deformation of thecompliant material caused by the input; and a processor coupled to theforce sensor and configured to determine a force associated with theinput based on the signal; wherein: the stud defines an opening; and theopening facilitates an electrical connection between the processor andthe force sensor.
 2. The watch of claim 1, wherein: the watch furthercomprises a position sensor configured to detect rotation of the crowncap; the force sensor comprises: a first electrode; a second electrode;a third electrode; a fourth electrode; and an insulating substratebetween the first electrode and the second electrode, and between thethird electrode and fourth electrode; the force sensor is configured todetect lateral movement of the crown cap based on a change incapacitance between the first electrode and the second electrode; theforce sensor is further configured to detect axial movement of the crowncap based on a change in capacitance between the third electrode and thefourth electrode; the display is configured to display one or moreindicia; and the display is configured to change the one or more indiciain response to the rotation, the lateral movement, or the axial movementof the crown cap.
 3. The watch of claim 1, further comprising: aflexible circuit positioned within the opening and extending from withinthe housing to the force sensor; wherein the flexible circuit comprisesthe electrical connection that electrically couples the processor to theforce sensor.
 4. The watch of claim 1, wherein: the stud comprises arotatable shaft; and the crown further comprises a positional sensorconfigured to detect an amount of rotation of the rotatable shaft. 5.The watch of claim 1, wherein: the stud comprises: a threaded portionconfigured to engage with the housing; a protruding portion at leastpartially surrounded by the compliant material; and a flange around thestud and positioned between the threaded portion and the protrudingportion; the threaded portion defines a hollow internal portion whichfacilitates the electrical connection.
 6. The watch of claim 5, furthercomprising: a fastener threadedly engaged with the stud and rigidlycoupling the stud to the housing.
 7. The watch of claim 1, wherein: thecrown cap is rotatable; and a positional sensor is coupled to the studand configured to detect an amount of rotation of the crown cap.
 8. Awatch crown, comprising: a stud configured to couple to a housing of anelectronic device thereby defining a protruding portion when coupled tothe housing; a compliant material surrounding at least a portion of theprotruding portion of the stud; a crown cap defining a recess, at leasta portion of the compliant material positioned in the recess, thecompliant material configured to deform in response to a movement of thecrown cap relative to the stud; a first sensor configured to transmit afirst signal in response to the movement of the crown cap relative tothe stud; a second sensor configured to transmit a second signal inresponse to the movement of the crown cap relative to the stud; and aprocessor coupled to the first sensor and the second sensor andconfigured to correlate the first signal and the second signal to aninput.
 9. The watch crown of claim 8, further comprising: a circuitcoupled to the first sensor and the second sensor, the circuit passingthrough and opening in the stud.
 10. The watch crown of claim 9, whereinthe compliant material at least partially fills the stud and encompassesthe circuit.
 11. The watch crown of claim 9, wherein the first sensorand the second sensor comprise: an insulating substrate; a flexibledrive circuit coupled to a first surface of the insulating substrate;and a flexible sense circuit coupled to a second surface of theinsulating substrate opposite the first surface.
 12. The watch crown ofclaim 11, wherein the insulating substrate, the flexible drive circuit,and the flexible sense circuit form a ring around an end of the stud.13. The watch crown of claim 8, wherein the compliant materialfacilitates less than complete rotation of the crown cap relative to thestud.
 14. The watch crown of claim 13, further comprising a positionsensor configured to transmit a third signal in response to rotation ofthe crown cap relative to the stud.
 15. An electronic watch comprising:a housing; a watch crown coupled to the housing and configured toreceive a force input, the watch crown comprising: a stud having aprotruding portion that extends outward from the housing; a crown capcoupled to the stud and defining a recess; a compliant materialsurrounding at least a portion of the stud and positioned at leastpartially in the recess, the compliant material configured to deform inresponse to a movement of the crown cap relative to the stud caused bythe force input; a first force sensor configured to detect a firstcomponent of the force input along a first direction; a second forcesensor configured to detect a second component of the force input alonga second direction different from the first direction; and a processingunit configured to, in response to the force input received at the watchcrown: determine a first force value using a first output from the firstforce sensor; determine a second force value using a second output fromthe second force sensor; and determine, using the first force value andthe second force value, an input direction of the force input.
 16. Theelectronic watch of claim 15, wherein the processing unit is furtherconfigured to determine, using the first force value and the secondforce value, that the force input corresponds to one or more of alateral input or a rotational input.
 17. The electronic watch of claim15, wherein the processing unit is further configured to: determine,using the first force value and the second force value, that the forceinput is unintended; and in response to determining that the force inputis unintended, reject the force input.
 18. The electronic watch of claim15, wherein: the electronic watch further comprises a display; and theprocessing unit is further configured to, in response to determining theinput direction of the force input, modify at least one of an indiciumdisplayed on the display or a brightness of the display according to theinput direction of the force input.
 19. The electronic watch of claim15, further comprising a positional sensor configured to detect a changein a rotational position of the watch crown.
 20. The electronic watch ofclaim 19, wherein the processing unit is further configured to, inresponse to the change in the rotational position of the watch crownexceeding a threshold, modify an indicium on a display of the electronicwatch.